1. Field of the Invention
The present invention relates to an electron source and an image forming apparatus as an application of the electron source.
2. Description of the Related Art
Conventionally, two types of devices, namely hot and cold cathode devices, are known as electron-emitting devices. Known examples of the cold cathode devices are field emission type electron-emitting devices (to be referred to as FE type electron-emitting devices hereinafter), metal/insulator/metal type electron-emitting devices (to be referred to as MIM type electron-emitting devices hereinafter), and surface-conduction emission (SCE) type electron-emitting devices.
Known examples of the FE type electron-emitting devices are described in W. P. Dyke and W. W. Dolan, xe2x80x9cField emissionxe2x80x9d, Advance in Electron Physics, 8, 89 (1956) and C. A. Spindt, xe2x80x9cPhysical properties of thin-film field emission cathodes with molybdenium conesxe2x80x9d, J. Appl. Phys., 47, 5248 (1976).
A known example of the MIM type electron-emitting devices is described in C. A. Mead, xe2x80x9cOperation of Tunnel-Emission Devicesxe2x80x9d, J. Appl. Phys., 32,646 (1961).
A known example of the surface-conduction emission type electron-emitting devices is described in, e.g., to Elinson, xe2x80x9cRadio Eng. Electron Phys., 10, 1290 (1965) and other examples will be described later.
The surface-conduction emission type electron-emitting device utilizes the phenomenon that electrons are a emitted from a small-area thin film formed on a substrate by flowing a current parallel through the film surface. The surface-conduction emission type electron-emitting device includes electron-emitting devices using an Au thin film [G. Dittmer, xe2x80x9cThin Solid Filmsxe2x80x9d, 9,317 (1972)], an In2O3/SnO2 thin film [M. Hartwell and C. G. Fonstad, xe2x80x9cIEEE Trans. ED Conf.xe2x80x9d, 519 (1975)), a carbon thin film [Hisashi Araki et al., xe2x80x9cVacuumxe2x80x9d, Vol. 26, No. 1, p. 22 (1983)], and the like, in addition to an SnO2 thin film according to Elinson mentioned above.
FIG. 36 is a plan view showing the device by M. Hartwell et al. described above as a typical example of the device structures of these surface-conduction emission type electron-emitting devices. Referring to FIG. 36, reference numeral 3001 denotes a substrate; and 3004, a conductive thin film made of a metal oxide formed by sputtering. This conductive thinfilm 3004 has anH-shaped pattern, as shown in FIG. 36. Anelectron-emittingportion 3005 is formed by performing electrification processing (referred to as forming processing to be described later) with respect to the conductivethin film 3004. An interval L in FIG. 36 is set to 0.5 to 1 mm, and a width W is set to 0.1 mm. The electron-emitting portion 3005 is shown in a rectangular shape at the center of the conductive thin film 3004 for the sake of illustrative convenience. However, this does not exactly show the actual position and shape of the electron-emitting portion.
In the above surface-conduction emission type electron-emitting devices by M. Hartwell et al. and the like, typically the electron-emitting portion 3005 is formed by performing electrification processing called forming processing for the conductive thin film 3004 before electron emission. In the forming processing, for example, a constant DC voltage or a DC voltage which increases at a very low rate of, e.g., 1 V/min is applied across the two ends of the conductive thin film 3004 to partially destroy or deform the conductive thin film 3004, thereby forming the electron-emitting portion 3005 with an electrically high resistance. Note that the destroyed or deformed part of the conductive thin film 3004 has a fissure. Upon application of an appropriate voltage to the conductive thin film 3004 after the forming processing, electrons are emitted near the fissure.
The above surface-conduction emission type electron-emitting devices are advantageous because they have a simple structure and can be easily manufactured. For this reason, many devices can be formed on a wide area. As disclosed in Japanese Patent Laid-Open No. 64-31332 filed by the present applicant, a method of arranging and driving a lot of devices has been studied.
Regarding applications of surface-conduction emission type electron-emitting devices to, e.g., image forming apparatuses such as an image display apparatus and an image recording apparatus, electron-beam sources, and the like have been studied.
As an application to image display apparatuses, in particular, as disclosed in the U.S. Pat. No. 5,066,883 and Japanese Patent Laid-Open No. 2-257551 filed by the present applicant, an image display apparatus using the combination of an surface-conduction emission type electron-emitting device and a fluorescent substance which emits light upon reception of an electron beam has been studied. This type of image display apparatus using the combination of the surface-conduction emission type electron-emitting device and the fluorescent substance is expected to have more excellent characteristics than other conventional image display apparatuses. For example, in comparison with recent popular liquid crystal display apparatuses, the above display apparatus is superior in that it does not require a backlight because it is of a self-emission type and that it has a wide view angle.
Other prior arts are disclosed in Japanese Patent Laid-Open Nos. 7-176265 and 8-248920. The prior art also includes Japanese Patent Laid-Open No. 9-134666.
It is an object of the present invention to realize a more preferable electron source manufacturing method, image forming apparatus manufacturing method, or electron source manufacturing apparatus.
According to the present invention, an electron source manufacturing method is characterized by comprising the step of applying a potential to first portions of a plurality of conductive members serving as at least part of electron-emitting devices via a wiring commonly connected to the plurality of conductive members, and applying a potential to second portions of the plurality of conductive members, thereby applying a voltage to the plurality of conductive members, wherein the potential applied to the second portions of the plurality of conductive members is set to relax a difference in voltage applied to the plurality of conductive members owing to a difference between potentials at portions respectively connected to the first portions of the plurality of conductive members in the wiring commonly connected to the plurality of conductive members.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.